Visual Corona 2 - 2017 Total Solar Eclipse

The solar corona is only visible for a few brief minutes during a total eclipse of the Sun.
Because the corona encompasses an enormous range of brightness (the innermost corona is over 1000 times brighter than the outer corona), it is difficult to capture an image that resembles what the eye sees.

It is a composite of 57 separate exposures (1/2000 to 2 seconds) shot with an Astro-Physics 105EDT refractor and a Nikon D800 DSLR.
The images were combined and processed using Photoshop CC 2017 and Photomatix Pro 6.
My PDF article "Digital Compositing Techniques for Coronal Imaging" is a bit dated (for example there is a discussion on digitizing negatives) but it still gives a detailed description of some of the digital processing techniques I used to process my 2017 eclipse images.

There is a tremendous amount of structure visible in the underlying data, but I have held back much of it to approximate what was actually seen visually and to avoid the heavily sharpened appearance that is common in HDR images.

The Moon appears darker than the sky because of the huge contrast between the Moon's disk and the very bright inner corona adjacent to the Moon.
I've tried to preserve this visual impression in this image.
A custom Curves layer was used to approximated the color to the dark blue sky.

Note the bright star Regulus (Alpha Leo) to the far left of the corona.